ToptCompare.kt

import com.bastiaanjansen.otp.HMACAlgorithm
import com.bastiaanjansen.otp.TOTP
import com.j256.twofactorauth.TimeBasedOneTimePasswordUtil
import dev.turingcomplete.kotlinonetimepassword.HmacAlgorithm
import dev.turingcomplete.kotlinonetimepassword.TimeBasedOneTimePasswordConfig
import dev.turingcomplete.kotlinonetimepassword.TimeBasedOneTimePasswordGenerator
import java.time.Duration
import java.time.Instant
import java.util.concurrent.TimeUnit
import javax.crypto.spec.SecretKeySpec

/*
Dependencies:

dependencies {
  implementation("dev.turingcomplete:kotlin-onetimepassword:2.2.0")
  implementation("com.github.bastiaanjansen:otp-java:1.3.0")
  implementation("com.eatthepath:java-otp:0.3.1")
  implementation("com.j256.two-factor-auth:two-factor-auth:1.3")
}
*/

fun main() {
  while(true) {
    val currentTime = System.currentTimeMillis()

    val timeStepSeconds = 30L
    val digits = 6

    val secretPlain = "#ug0sEABk,}@anh&<ozWM6,#Nq/<NC3s"
    val secretBase32 = "EN2WOMDTIVAUE2ZMPVAGC3TIEY6G66SXJU3CYI2OOEXTYTSDGNZQ" // Base32-encode `secretPlain`

    // dev.turingcomplete:kotlin-onetimepassword:2.2.0
    val config = TimeBasedOneTimePasswordConfig(timeStep = timeStepSeconds, timeStepUnit = TimeUnit.SECONDS, codeDigits = digits, hmacAlgorithm = HmacAlgorithm.SHA1)
    val kotlinOneTimePasswordGen = TimeBasedOneTimePasswordGenerator(secretPlain.toByteArray(), config)
    val kotlinOnetimePasswordCode = kotlinOneTimePasswordGen.generate(currentTime)

    // com.eatthepath:java-otp:0.3.1
    // https://github.com/jchambers/java-otp
    val eatthepath = com.eatthepath.otp.TimeBasedOneTimePasswordGenerator(Duration.ofSeconds(timeStepSeconds), digits, com.eatthepath.otp.TimeBasedOneTimePasswordGenerator.TOTP_ALGORITHM_HMAC_SHA1)
    val eatthepathCode = eatthepath.generateOneTimePasswordString(SecretKeySpec(secretPlain.toByteArray(), "RAW"), Instant.ofEpochMilli(currentTime))

    // com.github.bastiaanjansen:otp-java:1.3.0
    // https://github.com/BastiaanJansen/otp-java
    val bastiaanjansen = TOTP.Builder(secretBase32.toByteArray()).withAlgorithm(HMACAlgorithm.SHA1).withPasswordLength(digits).withPeriod(Duration.ofSeconds(timeStepSeconds)).build()
    val bastiaanjansenCode = bastiaanjansen.at(Instant.ofEpochMilli(currentTime))

    // com.j256.two-factor-auth:two-factor-auth:1.3
    // https://github.com/j256/two-factor-auth
    val j256Code = TimeBasedOneTimePasswordUtil.generateNumberString(secretBase32, System.currentTimeMillis(), timeStepSeconds.toInt(), digits)

    println("$kotlinOnetimePasswordCode - $eatthepathCode - $bastiaanjansenCode - $j256Code")

    Thread.sleep(2000)
  }
}